Insulator for high-potential lines.



Io. 7l7,322.' 'Patented' Dec. 30,1902.

c. E.'BABRY.

INSULATOB FOR HIGH POTENTIAL LINES.

(Application filed July 30, 1901.)

(N0 Ioddl.)

Witnesses: Inventor:

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UNITED STATES PATENT OEEIcE.

CHARLES E. BARRY, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

INSULATOR FOR HIGH-POTENTIAL LINES.

SPECIFICATION forming part of Letters Patent N 0. 717,322, dated December 30, 1902.

Application filed July 30 1901.

tial Lines, (Case No. 2,231,) of which the fol lowing is a specification.

This invention relates to conductor supports and insulators; and its object is to provide an insulating-connector for conductors carrying high-potential currents of electricity which shall combine great mechanical strength with good insulation. I accomplish the first result by making the insulator-frame of metal and the second by interposing insulating material between opposed portions of the frame and by so constructing the device that similar units can be added together in series until a sufficient degree of insulation is attained. By this expedient an insulator of any desired insulating value can be built up.

In the accompanying drawings, Figure 1 is a side elevation, partly in longitudinal section, of an insulator composed of three units. Fig. 2 is an end view of the same, partly in section.

Each unit of the insulator comprises a shallow metallic cup A, provided with a metallic cap B, having a central hole I) and, a screwthreaded flange b to engage with screwthreads on the outside of the cup. Inside the cup is a metallic disk 0, whose diameter is less than the interior of the cup, but greater than that of the hole I) in the cap. On the disk is a metallic stem C, projecting through the hole b and having means for rigidly attaching it to the bottom of the next cup. I prefer to provide the stem with a head 0, having screw-threads on its edge to mesh with a tapped hole in the bottom of the cup. A mass of insulating material D lies between the disk and the cup and cap and preferably extends along the stem C up to the head 0. The desired number of such units can be rigidly connected in a series by screwing the head 0 of one into the bottom of the next. One of the end units has the stem provided with an eye C while a special stem with an eye C is Serial No. 70,263. (No model.)

screwed or otherwise attached to the bottom of the other end unit.

Inasmuch as the disk C is larger than the hole I) the strain tending to pull the disk out of the cup will be sustained by the overlapping'edge of the cap. A sufiicient number of units must be used to have the combined thickness of the insulation sufficient to withstand the line-voltage, and the surface of insulation exposed between the stem and the edge of the hole 6 should be enough to preventsurface creeping of the current.

The lnetallicparts give great strength to this insulator, while the possibility of adding together a plurality of units renders it capable of use with any voltage, however high. It is of especial service in the span-wires supporting high-tension trolley-conductors.

I am aware that it is a common expedient to string together a plurality of separate insulators in a series; but my device differs from that in that it is a rigid structure which, if desired, can be built up and tested before being sent out or, on the other hand, can he readily put together by linemen. Moreover, it can be easily separated for repair or be added to in case of necessity.

. What I claim as new, and desire to secure by Letters Patent of the United States, is-

1. An insulator unit composed of a metallic cup having a screw-threaded hole in its bottom, a screw-cap having a central hole, a disk provided with a stem having a screwthreaded head, and insulation between the cup and cap and the disk and stem. 1

2. An insulator composed of a plurality of rigidly-connected units, each having a metallic cup, a screw-cap having a hole, a disk of greater diameter than the hole in the cap, a stem on the disk, means for rigidly attaching the stem to the bottom of the next cup, and insulation surrounding the disk and stem.

In witness whereof I have hereunto set my hand this 27th day of July, 1901.

CHARLES E. BARRY. 

